<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>

    // let i =1  //变量的起始值
    // let sum =0  //累加和变量
    // while(i <= 100){
    //   sum += i
    //   i++
    // }
    //  console.log(sum)

    let  i=1
    let sum =0
    while(i<=100){
      //筛选偶数
      if(i % 2===0){
        sum +=i
      }
      //每次循环自加
      i++
    }
    console.log(sum)
  </script>
</body>
</html>